Democrats pick first Hispanic for convention keynote address

San Antonio Mayor Julian Castro gives the keynote address at the Texas Democratic Convention in Houston on June 8. The Democratic Party announced Tuesday that Castro will deliver the keynote address at the Democratic National Convention on Sept. 4.

WASHINGTON — Marking a first for Hispanics, the Democratic party has chosen the mayor of San Antonio to deliver the keynote address at the Democratic National Convention.

The party announced Tuesday that Mayor Julian Castro will deliver the high-profile, prime-time address on the convention’s opening night, Sept. 4., in Charlotte, N.C.

First lady Michelle Obama will also address convention delegates — and a nationwide television audience — on the same night.

Castro, 37, is the youngest mayor of a major U.S. city and the first Hispanic selected to deliver the keynote address at the Democratic convention.

President Barack Obama is banking on Hispanic support in battleground states like Florida, Colorado and Nevada as he seeks to break away from Republican rival Mitt Romney. The race remains deadlocked less than four months before Election Day, though polls show Obama with a sizable lead over Romney among Hispanic voters.

The late-summer party conventions will set the tone for the fall campaign blitz. Obama will accept his party’s nomination the first week in September, while Romney will get the Republican nod in Tampa, Fla., a week earlier.

As keynote speaker, Castro will step into the same role that propelled Obama into the national political spotlight. Then a little-known state lawmaker running for the U.S. Senate from Illinois, Obama delivered the convention keynote in 2004, winning wide praise from Democrats as a rising star in the party.

Castro, in a video announcing his selection as keynote speaker, made his case for Obama’s re-election, arguing the president had begun to turn around the economy.

“We’ve come so far over the past three and a half years under Obama’s leadership,” he said. “And I know he’s not done yet. We got a lot more work to do.”

Democrats also announced that former President Bill Clinton and Elizabeth Warren, the party’s Senate candidate in Massachusetts, will have prime speaking roles at the convention Sept. 5.

Obama and Vice President Joe Biden will speak in prime time on the convention’s final night, Sept. 6, at an outdoor arena in Charlotte.

Castro’s star power among Democrats has skyrocketed since he became mayor in 2009. He made more than a dozen trips to Washington during his first term, including several to the White House, and has often been called on by the Obama administration to address immigration and energy policy.

The first resolution he wrote as mayor urged Texas lawmakers not to pursue an Arizona-style immigration law.

In his convention speech, Castro is likely to tell his personal story of being raised in San Antonio by a prominent Latino-rights advocate in the 1960s and 1970s with his twin brother, Joaquin, who is likely this November to win the congressional seat held by retiring Democratic Rep. Charlie Gonzalez. The brothers are Harvard law graduates and wield a rare Democratic celebrity in Texas, where Republicans hold all statewide offices.

Speculation about Castro’s political future has been constant since he became mayor, but Castro began his second term last year insisting he was in no hurry to leave.

San Antonio is the nation’s seventh-largest city and nearly two-thirds Hispanic. Castro often discusses how demographers project that the racial makeup of San Antonio is what Texas, and eventually much of the country, will grow to resemble in the coming decades.